efi/libstub: Allocate headspace in efi_get_memory_map()

efi_get_memory_map() allocates a buffer to store the memory map that it retrieves. This buffer may need to be reused by the client after ExitBootServices() is called, at which point allocations are not longer permitted. To support this usecase, provide the allocated buffer size back to the client, and allocate some additional headroom to account for any reasonable growth in the map that is likely to happen between the call to efi_get_memory_map() and the client reusing the buffer.

Jeffrey Hugo committed 10 years ago

Commit dadb57a1 parent 4af9ed55 files · +111 −49Browse files

Showing the changes to include/linux (1 of 5 files). Show all

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include/linux/efi.h+10−5

@@ -118,6 +118,15 @@ typedef struct { · 117 unmodified lines
118	118	u32 imagesize;
119	119	} efi_capsule_header_t;
120	120
	121	+struct efi_boot_memmap {
	122	+ efi_memory_desc_t **map;
	123	+ unsigned long *map_size;
	124	+ unsigned long *desc_size;
	125	+ u32 *desc_ver;
	126	+ unsigned long *key_ptr;
	127	+ unsigned long *buff_size;
	128	+};
	129	+
121	130	/*
122	131	* EFI capsule flags
123	132	*/
@@ -1371,11 +1380,7 @@ char efi_convert_cmdline(efi_system_table_t sys_table_arg, · 1247 unmodified lines
1371	1380	efi_loaded_image_t image, int cmd_line_len);
1372	1381
1373	1382	efi_status_t efi_get_memory_map(efi_system_table_t *sys_table_arg,
1374		− efi_memory_desc_t **map,
1375		− unsigned long *map_size,
1376		− unsigned long *desc_size,
1377		− u32 *desc_ver,
1378		− unsigned long *key_ptr);
	1383	+ struct efi_boot_memmap *map);
1379	1384
1380	1385	efi_status_t efi_low_alloc(efi_system_table_t *sys_table_arg,
1381	1386	unsigned long size, unsigned long align,